This is how to upload using 7zip! 7z compresses your files more than any other program. 7z is a free program found here
http://www.7-zip.org/download.html.
To use:
1) Pick any file(s) from anywhere
I picked two files
(DC) White Pass.esp
and
(DC) Sutch Reborn.esp
2) Pick one of the using 7z file manager I chose white pass, while the file is highlighted in the upper left area there is a green addition sign reading "ADD" click it.
3) You should get a popup menu after clicking add, on the top mine reads "(DC) The Town of White Pass.7z" Do not touch anything but compression level. Set it to "ultra" on the drop down menu.
4)click OK
5) Open the new 7z file you just made. Now just click and drag the files from any old windows folder straight to the 7z window its that easy!
6) All done! Now both of your files are in one 7z archive!